On 6 and 7 December democracy goes on trial in Turkey. Opposition politicians Selahattin Demirtaş and Figen Yüksekdağ will appear in court on trumped-up charges of terrorism, facing lengthy jail sentences. Their party, the People’s Democratic Party (HDP) is the third largest in Turkey. In 2015 they won parliamentary seats for the first time, representing a breakthrough for progressive forces and democracy in the country.

However, the state of emergency in place since the July 2016 coup attempt has been used to clamp down on all forms of opposition in Turkey. In November 2016 HDP MPs across the country were taken from their homes and detained. Currently there are nine MPs from the HDP in Turkish prisons along with 85 mayors and an estimated 10,000 activists. Journalists, academics and public sector workers have been purged from their posts. One million people are displaced in Turkey’s largely Kurdish south-east with cities including Cizre and Nusaybin flattened. The prosecutions of Demirtaş and Yüksekdağ are nothing more than show trials. We send a message of solidarity to Figen Yüksekdağ and Selahattin Demirtaş and demand their immediate and unconditional release from prison.Noam Chomsky Professor emeritus, MITClive Lewis MPDavid Lammy MPKate Osamor MPKaren Lee MPLen McCluskeyGeneral secretary, UniteLaura Smith MPJulie Ward MEPChris Williamson MPDr Kerem NisanciogluSOAS, University of Londonand London Middle East InstituteDr Adam Elliott-CooperKing’s College LondonDr Ayça ÇubukçuAssistant professor,LSE Centre for Human RightsRosa GilbertKurdistan Solidarity CampaignSteve Sweeney JournalistOktay SahbazSolidarity with the People of TurkeyManuel CortesTSSA General SecretaryDoug Nicholls GFTU General SecretaryGrahame Morris MPDan Carden MPIan Mearns MPSean HoyleRMT PresidentSteve HedleyRMT Assistant General SecretaryEddie DempseyRMT National Executive CommitteePaul GloverChair of Unison International CommitteeMartin Powell-DaviesLondon Regional Secretary, National Education UnionLouise Regan Joint National President, National Education UnionRob WilliamsNational Shop Stewards NetworkLindsey GermanStop the War Coalition ConvenorJohn ReesStop the War Coalition National OfficerPaul Maskey MPFrancie Molloy MP Michelle Gildernew MP Mickey Brady MPBarry McElduff MPElisha McCallion MPChris Hazzard MPPeter TatchellHuman Rights campaignerJulie HesmondhalghActorBarry White Campaign for Press and Broadcasting FreedomBen ChackoEditor, Morning StarLiz Davies• Join the debate – email guardian.letters@theguardian.com